.container {
  width: 300px;
  height: 300px;
  background: #FFF;
  display: flex;
  justify-content: center;
  align-items: center;
  filter: contrast(30);
}

.circle {
  border-radius: 50%;
  position: absolute;
  filter: blur(10px);
}

.circle_1 {
  width: 100px;
  height: 100px;
  background-color: #03a9f4;
  transform: translate(-50px);
  animation: 2s moving linear infinite alternate-reverse;
}

.circle_2 {
  height: 60px;
  width: 60px;
  background: #0000ff;
  transform: translate(50px);
  animation: 2s moving linear infinite alternate;
}

@keyframes moving {

  //两个元素的移动
  0% {
    transform: translate(50px)
  }

  100% {
    transform: translate(-50px)
  }
}